Insect gut bacterial diversity determined by environmental habitat, diet, developmental stage, and phylogeny of host.

Insects are the most abundant animals on Earth, and the microbiota within their guts play important roles by engaging in beneficial and pathological interactions with these hosts. In this study, we comprehensively characterized insect-associated gut bacteria of 305 individuals belonging to 218 species in 21 taxonomic orders, using 454 pyrosequencing of 16S rRNA genes. In total, 174,374 sequence reads were obtained, identifying 9,301 bacterial operational taxonomic units (OTUs) at the 3% distance level from all samples, with an average of 84.3 (± 97.7) OTUs per sample. The insect gut microbiota were dominated by Proteobacteria (62.1% of the total reads, including 14.1% Wolbachia sequences) and Firmicutes (20.7%). Significant differences were found in the relative abundances of anaerobes in insects and were classified according to the criteria of host environmental habitat, diet, developmental stage, and phylogeny. Gut bacterial diversity was significantly higher in omnivorous insects than in stenophagous (carnivorous and herbivorous) insects. This insect-order-spanning investigation of the gut microbiota provides insights into the relationships between insects and their gut bacterial communities.

Ferrimonas pelagia sp. nov., isolated from seawater.

A Gram-stain-negative bacterium, designated strain CBA4601(T), was isolated from a seawater sample obtained off the coast of Jeju Island, Korea. The organism grew in the presence of 0-4% (w/v) NaCl and at 20-35 °C and pH 7.0-9.0, with optimal growth in 2% NaCl, and at 25 °C and pH 8.0. Phylogenetic trees based on 16S rRNA gene sequences showed that strain CBA4601(T) was related to the genus Ferrimonas within the class Gammaproteobacteria. 16S rRNA gene sequence similarity between strain CBA4601(T) and Ferrimonas marina A4D-4(T), the most closely related species, was 96.9%. The G+C content of the genomic DNA from strain CBA4601(T) was 54.2 mol%, and the isoprenoid quinones menaquinone 7 (MK-7), ubiquinone 7 (Q-7) and ubiquinone 8 (Q-8) were detected. The major fatty acids were C(17:1)ω8c, C(18:1)ω9c and C(16:0), and the major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and an unidentified ninhydrin-positive phospholipid. On the basis of this taxonomic study using a polyphasic approach, strain CBA4601(T) represents a novel species of the genus Ferrimonas, for which the name Ferrimonas pelagia sp. nov. is proposed. The type strain is CBA4601(T) ( =KACC 16695(T) =KCTC 32029(T) =JCM 18401(T)).

Gillisia marina sp. nov., from seashore sand, and emended description of the genus Gillisia.

A Gram-staining-negative, strictly aerobic, rod-shaped bacterium, designated CBA3202(T), was isolated from seashore sand on Jeju Island, Republic of Korea. Based on the 16S rRNA gene sequence analysis, strain CBA3202(T) was allocated to the genus Gillisia (family Flavobacteriaceae) and was most closely related to the type strain of Gillisia mitskevichiae (99.0 % 16S rRNA gene sequence similarity). Optimal growth occurred at 25 °C and with 3 % NaCl. The only isoprenoid quinone was menaquinone-6 (MK-6), the predominant fatty acids were C16 : 0, iso-C15 : 1 G, iso-C16 : 0 and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), and the DNA G+C content was 34.9 mol%. The polar lipids were phosphatidylethanolamine, two unidentified aminolipids and several unidentified polar lipids. Based on phylogenetic inference and phenotypic data, we conclude that strain CBA3202(T) represents a novel species of the genus Gillisia, for which the name Gillisia marina sp. nov. is proposed. The type strain is CBA3202(T) ( = KACC 16693(T) = KCTC 32030(T) = JCM 18402(T)). An emended description of the genus Gillisia is also provided.

Genomic Analysis of the Extremely Halophilic Archaeon Halobacterium noricense CBA1132 Isolated from Solar Salt That Is an Essential Material for Fermented Foods.

The extremely halophilic archaeon Halobacterium noricense is a member of the genus Halobacterium. Strain CBA1132 (= KCCM 43183, JCM 31150) was isolated from solar salt. The genome of strain CBA1132 assembled with 4 contigs, including three rRNA genes, 44 tRNA genes, and 3,208 open reading frames. Strain CBA1132 had nine putative CRISPRs and the genome contained genes encoding metal resistance determinants: copper-translocating P-type ATPase (CtpA), arsenical pump-driving ATPase (ArsA), arsenate reductase (ArsC), and arsenical resistance operon repressor (ArsR). Strain CBA1132 was related to Halobacterium noricense, with 99.2% 16S rRNA gene sequence similarity. Based on the comparative genomic analysis, strain CBA1132 has distinctly evolved; moreover, essential genes related to nitrogen metabolism were only detected in the genome of strain CBA1132 among the reported genomes in the genus Halobacterium. This genome sequence of Halobacterium noricense CBA1132 may be of use in future molecular biological studies.

Draft genome sequence of the agarolytic haloarchaeon Halobellus rufus type strain CBA1103.

The extremely halophilic archaeon Halobellus rufus type strain CBA1103(T) (CECT 8423(T) and JCM 19434(T)) was isolated from non-purified solar salt and characterized as an agarase producer. The draft genome sequence contains 3852 303 bp with a G + C content of 64.1% and includes genomic information on various carbohydrate-active enzymes. This is the first sequenced genome of the genus Halobellus, and is expected to provide general sequence information for halophilic carbohydrate-active enzymes and opportunities for biotechnological applications of novel halophilic enzymes.

Draft genome sequence of the extremely halophilic archaeon Haladaptatus cibarius type strain D43(T) isolated from fermented seafood.

An extremely halophilic archaeon, Haladaptatus cibarius D43(T), was isolated from traditional Korean salt-rich fermented seafood. Strain D43(T) shows the highest 16S rRNA gene sequence similarity (98.7 %) with Haladaptatus litoreus RO1-28(T), is Gram-negative staining, motile, and extremely halophilic. Despite potential industrial applications of extremely halophilic archaea, their genome characteristics remain obscure. Here, we describe the whole genome sequence and annotated features of strain D43(T). The 3,926,724 bp genome includes 4,092 protein-coding and 57 RNA genes (including 6 rRNA and 49 tRNA genes) with an average G + C content of 57.76 %.

Genome sequence of the haloarchaeon Haloterrigena jeotgali type strain A29(T) isolated from salt-fermented food.

Haloterrigena jeotgali is a halophilic archaeon within the family Natrialbaceae that was isolated from shrimp jeotgal, a traditional Korean salt-fermented food. A29(T) is the type strain of H. jeotgali, and is a Gram-negative staining, non-motile, rod-shaped archaeon that grows in 10 %-30 % (w/v) NaCl. We present the annotated H. jeotgali A29(T) genome sequence along with a summary of its features. The 4,131,621 bp genome with a GC content of 64.9 % comprises 4,215 protein-coding genes and 127 RNA genes. The sequence can provide useful information on genetic mechanisms that enable haloarchaea to endure a hypersaline environment.

Draft genome sequence of the extremely halophilic archaeon Halococcus sediminicola CBA1101T isolated from a marine sediment sample.

Halococcus sediminicola CBA1101T (=CECT 8275T, JCM 18965T) is an extremely halophilic strain isolated from a marine sediment collected from the bay of Gangjin in the Republic of Korea. We found that the draft genome of H. sediminicola CBA1101T contains 3,764,367bp, with 62.3% G+C content. This is the one of the few genomes to be sequenced in the genus Halococcus.